More detailed (and much longer) textbook Mastering Dyalog APL by Bernard Legrand – this is written for Dyalog for Microsoft Windows, but the language elements (most of the content) applies to all platforms:

Documentation

The Dyalog for Raspberry Pi User Guide includes details on installing and running Dyalog on your Raspberry Pi. Additional documentation is available in the /opt/mdyalog/<version>/32/unicode/help/ directory once you have installed Dyalog APL.

Support

Informal support is available through the Dyalog forums. Users with Commercial or Enterprise licences, or those who purchase DSS membership are entitled to formal dedicated support.

Why APL?

APL is great if you're working on an unsolved problem that involves complex algorithms or large volumes of data. APL's interactive development and powerful, concise, expressive notation offer a quick route from idea to working code. Like many excellent languages, APL can change and expand the way you think about problems and their solution. APL has been used with great success for learning and teaching in the STEM (Science, Technology, Engineering and Mathematics) areas. Its bit-manipulation capabilities make it a great tool for embedded, robotics and computer vision applications. This makes APL is a highly attractive notation for expressing solutions to many of the computational challenges that Raspberry Pi projects are likely to encounter at all levels of education or business. And it's fun!

About the Raspberry Pi

The Raspberry Pi is a single-board computer developed in the United Kingdom by the Raspberry Pi Foundation. By September 2016 over 10 million units had been sold – an amazing achievement for a product that was launched just over four years earlier.

The four-core Raspberry Pi model 3 has four cores and 1 GB of RAM. With the latest (Pixel) version of the operating system, the Raspberry Pi performs about as well as a low-end desktop or laptop computer.

The base cost for the Raspberry Pi model 3 is £35; you will need additional hardware to use it and should expect to pay £50-£75, excluding a monitor.

The low-cost, low-power, Raspberry Pi zero costs about £4 excluding postage. It needs additional hardware, and the full cost is likely to be £15-£50 depending on the options you chose, excluding a monitor.

If you're using a Raspberry Pi to experiment with APL, you'll get much more performance out of the Raspberry Pi model 3, and the total cost will not be much greater. If you're building a project where cost, space or power consumption are critical, then the Raspberry Pi zero may be a good choice.

Additional Information

Sample code for Dyalog on the Raspberry Pi is available from the https://github.com/APLPi open source repository. This repository will be maintained and extended as the Dyalog for Raspberry Pi project develops.